Remove need for homebrew/cask to be tapped

Library/Homebrew/cask/cask.rb

@@ -6,6 +6,7 @@ require "cask/config"
 require "cask/dsl"
 require "cask/metadata"
 require "searchable"
+require "api"
 
 module Cask
   # An instance of a cask.
@@ -130,14 +131,21 @@ module Cask
         return []
       end
 
+      latest_version = if ENV["HOMEBREW_JSON_CORE"].present? &&
+                          (latest_cask_version = Homebrew::API::Versions.latest_cask_version(token))
+        DSL::Version.new latest_cask_version.to_s
+      else
+        version
+      end
+
       installed = versions
       current   = installed.last
 
       # not outdated unless there is a different version on tap
-      return [] if current == version
+      return [] if current == latest_version
 
       # collect all installed versions that are different than tap version and return them
-      installed.reject { |v| v == version }
+      installed.reject { |v| v == latest_version }
     end
 
     def outdated_info(greedy, verbose, json, greedy_latest, greedy_auto_updates)

Library/Homebrew/cli/named_args.rb

@@ -45,18 +45,18 @@ module Homebrew
       # the formula and prints a warning unless `only` is specified.
       sig {
         params(
-          only:                     T.nilable(Symbol),
-          ignore_unavailable:       T.nilable(T::Boolean),
-          method:                   T.nilable(Symbol),
-          uniq:                     T::Boolean,
-          prefer_loading_from_json: T::Boolean,
+          only:                    T.nilable(Symbol),
+          ignore_unavailable:      T.nilable(T::Boolean),
+          method:                  T.nilable(Symbol),
+          uniq:                    T::Boolean,
+          prefer_loading_from_api: T::Boolean,
         ).returns(T::Array[T.any(Formula, Keg, Cask::Cask)])
       }
       def to_formulae_and_casks(only: parent&.only_formula_or_cask, ignore_unavailable: nil, method: nil, uniq: true,
-                                prefer_loading_from_json: false)
+                                prefer_loading_from_api: false)
         @to_formulae_and_casks ||= {}
         @to_formulae_and_casks[only] ||= downcased_unique_named.flat_map do |name|
-          load_formula_or_cask(name, only: only, method: method, prefer_loading_from_json: prefer_loading_from_json)
+          load_formula_or_cask(name, only: only, method: method, prefer_loading_from_api: prefer_loading_from_api)
         rescue FormulaUnreadableError, FormulaClassUnavailableError,
                TapFormulaUnreadableError, TapFormulaClassUnavailableError,
                Cask::CaskUnreadableError
@@ -90,11 +90,11 @@ module Homebrew
         end.uniq.freeze
       end
 
-      def load_formula_or_cask(name, only: nil, method: nil, prefer_loading_from_json: false)
+      def load_formula_or_cask(name, only: nil, method: nil, prefer_loading_from_api: false)
         unreadable_error = nil
 
         if only != :cask
-          if prefer_loading_from_json && ENV["HOMEBREW_JSON_CORE"].present? &&
+          if prefer_loading_from_api && ENV["HOMEBREW_JSON_CORE"].present? &&
              Homebrew::API::Bottle.available?(name)
             Homebrew::API::Bottle.fetch_bottles(name)
           end
@@ -133,9 +133,14 @@ module Homebrew
         end
 
         if only != :formula
+          if prefer_loading_from_api && ENV["HOMEBREW_JSON_CORE"].present? &&
+             Homebrew::API::CaskSource.available?(name)
+            contents = Homebrew::API::CaskSource.fetch(name)
+          end
+
           begin
             config = Cask::Config.from_args(@parent) if @cask_options
-            cask = Cask::CaskLoader.load(name, config: config)
+            cask = Cask::CaskLoader.load(contents || name, config: config)
 
             if unreadable_error.present?
               onoe <<~EOS

Library/Homebrew/cmd/install.rb

@@ -155,7 +155,7 @@ module Homebrew
     end
 
     begin
-      formulae, casks = args.named.to_formulae_and_casks(prefer_loading_from_json: true)
+      formulae, casks = args.named.to_formulae_and_casks(prefer_loading_from_api: true)
                             .partition { |formula_or_cask| formula_or_cask.is_a?(Formula) }
     rescue FormulaOrCaskUnavailableError, Cask::CaskUnavailableError => e
       retry if Tap.install_default_cask_tap_if_necessary(force: args.cask?)

Library/Homebrew/cmd/reinstall.rb

@@ -85,6 +85,9 @@ module Homebrew
   def reinstall
     args = reinstall_args.parse
 
+    # We need to use the bottle API instead of just using the formula file
+    # from an installed keg because it will not contain bottle information.
+    # As a consequence, `brew reinstall` will also upgrade outdated formulae
     if ENV["HOMEBREW_JSON_CORE"].present?
       args.named.each do |name|
         formula = Formulary.factory(name)

Library/Homebrew/cmd/update.sh

@@ -648,7 +648,8 @@ EOS
     # HOMEBREW_UPDATE_PREINSTALL wasn't modified in subshell.
     # shellcheck disable=SC2031
     if [[ -n "${HOMEBREW_JSON_CORE}" ]] && [[ -n "${HOMEBREW_UPDATE_PREINSTALL}" ]] &&
-       [[ "${DIR}" = "${HOMEBREW_LIBRARY}/Taps/homebrew/homebrew-core" ]]
+       [[ "${DIR}" = "${HOMEBREW_LIBRARY}/Taps/homebrew/homebrew-core" ||
+          "${DIR}" = "${HOMEBREW_LIBRARY}/Taps/homebrew/homebrew-cask" ]]
     then
       continue
     fi

Library/Homebrew/cmd/upgrade.rb

@@ -225,6 +225,15 @@ module Homebrew
   def upgrade_outdated_casks(casks, args:)
     return false if args.formula?
 
+    if ENV["HOMEBREW_JSON_CORE"].present?
+      casks = casks.map do |cask|
+        next cask if cask.tap.present? && cask.tap != "homebrew/cask"
+        next cask unless Homebrew::API::CaskSource.available?(cask.token)
+
+        Cask::CaskLoader.load Homebrew::API::CaskSource.fetch(cask.token)
+      end
+    end
+
     Cask::Cmd::Upgrade.upgrade_casks(
       *casks,
       force:          args.force?,

Library/Homebrew/extend/os/mac/tap.rb

@@ -4,7 +4,7 @@
 class Tap
   def self.install_default_cask_tap_if_necessary(force: false)
     return false if default_cask_tap.installed?
-
+    return false if ENV["HOMEBREW_JSON_CORE"].present?
     return false if !force && Tap.untapped_official_taps.include?(default_cask_tap.name)
 
     default_cask_tap.install